Multi-drive systems are employed in a variety of automated industrial applications in which two or more motor drives are operated via a distributed power system, typically using power derived from a shared AC or DC power source. High resistance grounding (HRG) is often employed in such power distribution configurations to allow system components to continue operation during ground fault conditions, with high grounding impedances being used to limit the amount of ground fault current to allow continued safe system operation as well as to facilitate detection of ground faults. When a ground fault situation is detected, however, it may be difficult to identify the source of the fault condition, particularly where many motor drives are connected to a single power source. In a typical situation, service personnel must shut down or deactivate all the drives on a shared DC bus or shared AC connection, and repeatedly test individual drives in an often lengthy process of elimination to determine which drive has a grounding problem. At each drive, a ground current measurement must be taken while the drive is running, which prevents usage of that drive and the other deactivated drives during the troubleshooting procedure, and also requires operation of the connected motor for ground fault testing, which may be disadvantageous in certain manufacturing situations. Conventional techniques for locating the source of ground faults are thus time-consuming and costly in terms of system downtime as well as labor costs for service personnel. Accordingly, a need remains for improved techniques and apparatus for ground fault location determination in motor drive systems.